Elastomer tire sealing ring

Abstract

An elastomeric tire sealing ring for installation against a rim of a wheel to provide a sealing surface with a tire bead of a tire when a tire is installed on the wheel over the sealing ring, the sealing ring comprising a thermoplastic composition wherein the thermoplastic composition has a durometer reading of between 36 and 50 on the Shore D scale as per ISO 868; and a tensile strength of 7.0 MPa to 8.9 MPa at 10% elongation as determined with ISO 527 method.

The invention claimed is: 
     
       1. An elastomeric tire sealing ring for installation against a rim of a wheel to provide a sealing surface with a tire bead of a tire when a tire is installed on the wheel over the sealing ring, the sealing ring comprising a thermoplastic elastomer and having a cross-sectional contour that is conformable to the outer surfaces of the rim when exposed to air pressure when the tire is inflated over the wheel;
 wherein the thermoplastic elastomer has a durometer reading of between 36 and 50 on the Shore D scale as per ISO 868; and a tensile strength of 7.0 MPa to 8.9 MPa at 10% elongation as determined with ISO 527 method; 
 wherein the average wall thickness of the sealing ring before installation is in the range of 0.3 mm to 0.7 mm; 
 wherein the thermoplastic elastomer has a melt temperature of 190 to 210° C., as determined with ISO Method 11357-1/-3; 
 wherein the rim has three or more rim drops; two outer rim drops having equal cross-sectional contours and an inner rim drop, said outer rim drops having in connecting-sequence from the outer edge of the rim: a rim vertical surface plane used in seating the tire bead, an outer drop bottom having an angled surface line, and a protrusion; 
 wherein said outer drop bottom has a drop bottom minimum wherein said drop bottom minimum defines the intersection of an outer rim drop bottom tangent line that also is parallel to the rotational axis of the wheel; 
 wherein the intersection of the angled surface line and the outer rim drop bottom tangent line defines an rim outer drop bottom angle (Alpha); and said tire sealing ring has at least three sealing ring drops, at least two outer sealing ring drops and an inner sealing ring drop; at least one of said outer sealing ring drops having in connecting sequence: a sealing ring seating surface used in seating the tire bead; a sealing ring outer drop bottom having a surface line; said surface line intersecting with the outer rim drop bottom tangent line and defining an angle (Beta); wherein said angle (Beta) is 1.5 to 4 times larger than angle (Alpha), and 
 wherein the inner rim drop has an inner rim drop bottom minimum positioned at a depth D 1  from said outer rim drop bottom tangent line; and said inner sealing ring drop has a inner sealing ring bottom minimum positioned at a depth D 2  from the outer rim drop bottom tangent line; 
 wherein the ratio of D 2 :D 1  is 0.2 to 0.95. 
 
     
     
       2. The tire sealing ring of  claim 1 , wherein said angle (Beta) is 2 to 3 times larger than angle (Alpha) and wherein the ratio of D 2 :D 1  is 0.5 to 0.9. 
     
     
       3. The tire sealing ring of  claim 2 , wherein said inner sealing ring drop has one or more undulations. 
     
     
       4. The tire sealing ring of  claim 2 , having an integrally formed projecting valve stem dimple. 
     
     
       5. The elastomeric tire sealing ring of  claim 1 , wherein said elastomers is a copolyetherester.